ROI(感興趣區域)編碼是一種新的功能包含在JPEG2000圖像編碼標準。JPEG2000提供ROI編碼是透過兩個機制: 修改小波係數或者使用率失真優化技術，而這兩種機制都各有優缺點。本論文提出一種基於CCSDS壓縮演算法為核心的多個感興趣區域編碼方法。我們提出的方法，不會將編碼效率降低，以及容易實作，而保持CCSDS的標準。不論是在整張壓縮(full-frame)或是帶狀壓縮(strip-based)，亦可以實現多個感興趣區域編碼。首先，我們會將小波係數，按照使用者輸入的ROI 遮罩，分割成數個 ROI 及 非ROI(背景) 的Segment，再依照使用者輸入的整體壓縮比來計算出不同Segment所獲得分配的位元個數，最後以CCSDS標準壓縮輸出串流位元。

Region-of-Interests (ROI) coding is a new feature included in the JPEG2000 image coding standard. JPEG2000 provides two mechanisms in the ROI coding: modifying wavelet coefficients or using rate-distortion optimization techniques, which have their respective advantages and disadvantages. This paper proposed a multiple Region-of-Interests (ROI) coding based on CCSDS algorithm. The proposed method is easy to implement and maintains the CCSDS standards without reducing the coding efficiency. The multiple region of interest can be encoded regardless of a full frame-based method or a strip-based one. At first, we divided the wavelet coefficients into a number of ROI and non-ROI (background) segments according to the ROI mask assigned by the user. Secondly, the encoder calculates the bit allocation of each segment according to the overall compression ratio assigned by the user. Finally, we encode and output the bit stream by CCSDS Recommended Standard compression.

[1] Amir Said and William A. Pearlman, “A new, fast, and efficient image codec based on set partitioning in hierarchical tress,” IEEE Trans. Circuits and Systems for Video Technology, Vol. 6, p243-250, June, 1996.

[2] Athanassios Skodras, Charilaos Christopoulos, and Touradj Ebrahimi, “The JPEG2000 still image compression standard,” IEEE Signal Processing Mag., pp. 36–58, Sept. 2001.

[3] CCSDS Information Report (Green Book): Image Data Compression (CCSDS 120.1-G-1), Issue 1, June, 2007

[4] CCSDS Recommended Standard (Blue Book): Image Data Compression (CCSDS 122.0-B-1), Issue 1, Nov., 2005

[5] Charles K. Chui, “An Introduction to Wavelets, ” Academic Press, SanDiego, ISBN 0585470901, 1992

[6] David S. Taubman and Michael W. Marcellin., “JPEG 2000 : Image Compression Fundaments, Standards and Practice,” Norwell, MA:Kluwer, 2002.

[7] Jerome M. Shapiro, “Embedded image coding using zerotrees of wavelet coefficients,”IEEE Transactions on Signal Processing, Vol 41, No. 12, p. 3445-3462, 1993.

[8] Joel Askelöf, Mathias Larsson Carlander,Charilaos Christopoulos, “Region of interest coding in JPEG 2000,” Elsevier Signal Processing: Image Communication 17, page 105-111, 2002.

[9] JPEG 2000 Part I: Final Draft International Standard (ISO/IECFDIS15444-1), ISO/IECJTC1/SC29/WG1 N1855, Aug. 2000.

[10] Kkeun-hyeong Park, Chul Soo Lee and Hyun Wook Park, “Region-of-interest coding based on Set Partitioning In Hierarchical Trees,” Circuits and Systems for Video Technology, IEEE Transactions on, Volume 12, Issue 2, p106-113, 2002